1. Technical Field
The invention relates to artificial fuels and in particular to a fuel block formed of compressed combustible particles and a binder. More particularly, the invention relates to such a fuel block having a controlled burning rate so that the fuel block will burn over extended periods of time. More particularly, the invention relates to such a fuel block used in preventing frost damage to citrus fruit trees.
2. Background Information
Various types of heaters and fuels are used to prevent damage to fruit trees and the fruit thereon due to frost. These prior fuel devices are usually mechanical type stoves containing various types of liquid fuels such as oil, kerosene or the like. The stoves are placed beneath the fruit trees or adjacent to a number of trees, and are lighted in an attempt to produce sufficient heat to prevent frost from damaging the trees and fruit. Although certain of these heater devices are satisfactory, they provide certain undesirable characteristics such as environmentally unsatisfactory fumes and particulate discharge, as well as the expense involved for the heating fluid used therein. Also, it requires the transportation and storage of the numerous heaters and fuel during the majority of the growing season since such heaters are used only occasionally, but are absolutely essential at such times to prevent destruction of the trees and fruit.
Upon an expected frost, the fruit growers must transport all of the heaters from storage and place the same along the trees and then fill the heaters with the heating fluid which is usually kept in a mobile storage tanker. All of this equipment and labor intensive activity, increases the production costs to the fruit grower.
Artificial fuel logs usually comprised of compressed sawdust and various wax binders and other combustible fillers and igniters, have been developed over the years primarily for use in a home fireplace. Examples of such artificial fireplace logs are shown in U.S. Pat. Nos. 2,789,890, 4,104,034, 4,120,666, 4,147,518, 4,243,394, 4,043,765, 4,040,796, 3,726,651 and D 311,578. Some of these artificial firelogs are formed with center holes and outer grooves extending throughout the length of the logs, to enhance the burning thereof. These logs also are provided with various wrappers for protecting the log from the environment as well as providing a readily available combustible material to assist in igniting the log.
Although these artificial fireplace logs are satisfactory for their intended use, they have a relatively short burning time since the main desire of such logs is to simulate a regular burning wood log. Thus, the log will burn throughout its entire length and circumference at about the same time. Therefore, once these artificial logs are ignited, the entire log will generally burn throughout its length which results in a relatively short burning time, three hours being the normal burn length of most artificial firelogs in use today. Although these firelogs could be used for the protection of fruit trees, their short burning lengths would require several logs to be burned successively to adequately protect the trees which would result in considerable expenditure of man hours of labor, equipment and logs.
Therefore, the need exists for an improved fuel block preferably formed of a compressed combustible material which has a sufficient burning time and heat emission to prevent frost damage to fruit trees and fruit, without requiring excessive amounts of combustible material and weight to achieve such burn time and heat emission, and in which less man hours are required for use of the fuel blocks than heretofore required with the standard mechanical heaters and separate liquid fuel; and in which the fuel blocks can be placed in position for usage prior to the anticipated frost to ensure that the same are readily available should a sudden frost occur.